1. Decorative color of coatings is currently available in gold color system, imitation gold color system, gray and black color system, brown coffee color system, blue color system, seven color system and so on. In general, the color is still relatively limited, especially for those more vivid colors, anode dyeing or spray is better than PVD coatings. Besides, the targets used now are gold targets, rose gold targets, titanium targets, zirconium targets, titanium aluminum targets, tungsten targets, graphite targets, etc., the choices are relatively limited. The industry needs to break through these bottlenecks, introduce more targets and develop more colors.

2. The PVD process itself is environmentally friendly, but it requires a lot of chemical products for its pre-cleaning and decoating. Today, environment requirement is increasing, so the industry needs a good method to replace these processes.

3. The decorative coating is very thin, with certain porosity, it cannot be completely isolated with the surface of the workpiece, and the anti-corrosion performance needs to be improved. Another reason for low corrosion resistance is that the plating, corrosive media, and workpieces form a corrosive cell, and the plated layer and the substrate become electrode corner, resulting in electrochemical corrosion.

4. PVD decorative coating has requirements on the substrate. At present, the most widely used is stainless steel. In recent years, some people have tried to directly perform PVD treatment on the surface of aluminum. Although there are some breakthroughs, there is no large-scale industrial application.